There is flip side, which is at least (if not more) unfortunate. The really-really bad thing about sweatshops is not that they exist, but that they are, as sad as it is, often the least-bad option for locals. Press too hard or too much and they will shut down - which will mean that the same amount of people will have even less choice of jobs and thus will be forced to work under even worse conditions.

Also, don't mix human rights with profits. A daily $1 salary is a $1 salary no matter what your rights are (take for example Europe - human rights are largely balanced throughout and still the taxes/salaries in different countries vary quite a bit, making certain countries preferred for new plants and investments).